General Description
The MIC3203 is a hysteretic, step-down, constant-current, High-Brightness LED (HB LED) driver. It provides an ideal solution for interior/exterior lighting, architectural and ambient lighting, LED bulbs, and other general illumination applications.
The MIC3203 is well suited for lighting applications requiring a wide-input voltage range. The hysteretic control gives good supply rejection and fast response during load transients and PWM dimming. The high-side current sensing and on-chip current-sense amplifier delivers LED current with ±5% accuracy. An external high-side current sense resistor is used to set the output current.
The MIC3203 offers a dedicated PWM input (DIM) which enables a wide range of pulsed dimming. A high-frequency switching operation up to 1.5MHz allows the use of smaller external components minimizing space and cost. The MIC3203 offers frequency dither feature for EMI control.
The MIC3203 operates over a junction temperature from −40°C to +125°C and is available in an 8-pin SOIC package.
A dither disabled version MIC3203-1 is also available in the same package as the MIC3203.

Features
• 4.5V to 42V input voltage range
• High efficiency (>90%)
• ±5% LED current accuracy
• MIC3203: Dither enabled for low EMI
• MIC3203-1: Dither disabled
• High-side current sense
• Dedicated dimming control input
• Hysteretic control (no compensation!)
• Up to 1.5MHz switching frequency
• Adjustable constant LED current
• Over-temperature protection
• −40°C to +125°C junction temperature range

Applications
• Architectural, industrial, and ambient lighting
• LED bulbs
• Indicators and emergency lighting
• Street lighting
• Channel letters
• 12V lighting systems (MR-16 bulbs, under-cabinet
   lighting, garden/pathway lighting)